/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*- * vim:expandtab:shiftwidth=8:tabstop=8: * * GPL HEADER START * * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 only, * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License version 2 for more details (a copy is included * in the LICENSE file that accompanied this code). * * You should have received a copy of the GNU General Public License * version 2 along with this program; If not, see * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * * GPL HEADER END */ /* * Copyright 2008 Sun Microsystems, Inc. All rights reserved * Use is subject to license terms. */ /* * This file is part of Lustre, http://www.lustre.org/ * Lustre is a trademark of Sun Microsystems, Inc. * * lustre/ldlm/ldlm_inodebits.c * * Author: Peter Braam * Author: Phil Schwan */ #define DEBUG_SUBSYSTEM S_LDLM #ifndef __KERNEL__ # include #endif #include #include #include #include "ldlm_internal.h" /* Determine if the lock is compatible with all locks on the queue. */ static int ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req, struct list_head *work_list) { struct list_head *tmp; struct ldlm_lock *lock; ldlm_mode_t req_mode = req->l_req_mode; __u64 req_bits = req->l_policy_data.l_inodebits.bits; int compat = 1; ENTRY; LASSERT(req_bits); /* There is no sense in lock with no bits set, I think. Also such a lock would be compatible with any other bit lock */ list_for_each(tmp, queue) { struct list_head *mode_tail; lock = list_entry(tmp, struct ldlm_lock, l_res_link); if (req == lock) RETURN(compat); /* last lock in mode group */ LASSERT(lock->l_sl_mode.prev != NULL); mode_tail = &list_entry(lock->l_sl_mode.prev, struct ldlm_lock, l_sl_mode)->l_res_link; /* locks are compatible, bits don't matter */ if (lockmode_compat(lock->l_req_mode, req_mode)) { /* jump to last lock in mode group */ tmp = mode_tail; continue; } if (lock->l_req_mode == LCK_COS) { if (lock->l_client_cookie == req->l_client_cookie) { tmp = mode_tail; } else { tmp = mode_tail; if (!work_list) RETURN(0); compat = 0; if (lock->l_blocking_ast) ldlm_add_ast_work_item(lock, req, work_list); } continue; } for (;;) { struct list_head *head; /* last lock in policy group */ tmp = &list_entry(lock->l_sl_policy.prev, struct ldlm_lock, l_sl_policy)->l_res_link; /* locks with bits overlapped are conflicting locks */ if (lock->l_policy_data.l_inodebits.bits & req_bits) { /* conflicting policy */ if (!work_list) RETURN(0); compat = 0; /* add locks of the policy group to * @work_list as blocking locks for * @req */ if (lock->l_blocking_ast) ldlm_add_ast_work_item(lock, req, work_list); head = &lock->l_sl_policy; list_for_each_entry(lock, head, l_sl_policy) if (lock->l_blocking_ast) ldlm_add_ast_work_item(lock, req, work_list); } if (tmp == mode_tail) break; tmp = tmp->next; lock = list_entry(tmp, struct ldlm_lock, l_res_link); } /* loop over policy groups within one mode group */ } /* loop over mode groups within @queue */ RETURN(compat); } /* If first_enq is 0 (ie, called from ldlm_reprocess_queue): * - blocking ASTs have already been sent * - must call this function with the ns lock held * * If first_enq is 1 (ie, called from ldlm_lock_enqueue): * - blocking ASTs have not been sent * - must call this function with the ns lock held once */ int ldlm_process_inodebits_lock(struct ldlm_lock *lock, int *flags, int first_enq, ldlm_error_t *err, struct list_head *work_list) { struct ldlm_resource *res = lock->l_resource; CFS_LIST_HEAD(rpc_list); int rc; ENTRY; LASSERT(list_empty(&res->lr_converting)); check_res_locked(res); if (!first_enq) { LASSERT(work_list != NULL); rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, NULL); if (!rc) RETURN(LDLM_ITER_STOP); rc = ldlm_inodebits_compat_queue(&res->lr_waiting, lock, NULL); if (!rc) RETURN(LDLM_ITER_STOP); ldlm_resource_unlink_lock(lock); ldlm_grant_lock(lock, work_list); RETURN(LDLM_ITER_CONTINUE); } restart: rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, &rpc_list); rc += ldlm_inodebits_compat_queue(&res->lr_waiting, lock, &rpc_list); if (rc != 2) { /* If either of the compat_queue()s returned 0, then we * have ASTs to send and must go onto the waiting list. * * bug 2322: we used to unlink and re-add here, which was a * terrible folly -- if we goto restart, we could get * re-ordered! Causes deadlock, because ASTs aren't sent! */ if (list_empty(&lock->l_res_link)) ldlm_resource_add_lock(res, &res->lr_waiting, lock); unlock_res(res); rc = ldlm_run_ast_work(&rpc_list, LDLM_WORK_BL_AST); lock_res(res); if (rc == -ERESTART) GOTO(restart, -ERESTART); *flags |= LDLM_FL_BLOCK_GRANTED; } else { ldlm_resource_unlink_lock(lock); ldlm_grant_lock(lock, NULL); } RETURN(0); }